Re: [PATCH bpf-next 1/4] xsk: avoid store-tearing when assigning queues

On Thu, 22 Aug 2019 at 15:26, Hillf Danton [off-list ref] wrote:

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   /* Make sure queue is ready before it can be seen by others */

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   smp_wmb();

Hehe, who put mb here and for what?

That was from an earlier commit, and it's a barrier paired with the
lock-less reading of queues in xsk_mmap. Uhm... not sure I answered
your question?


Björn

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-   *queue = q;

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+  WRITE_ONCE(*queue, q);

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   return 0;